A known door lock device includes a latch mechanism provided at a vehicle door and engageable with or disengageable from a striker provided at a vehicle-body, a lift lever for operating the latch mechanism from an engaged state to a disengaged state by engaging with or disengaging from the striker, an open lever operated by an operation of a door opening member provided at the vehicle door, and a lock lever movable between an unlocked position and a locked position by an operation of a door locking/unlocking member provided at the vehicle door. The known door lock device further includes an open member operated with the lock lever and movable between the unlocked position and the locked position. When the open member is in the unlocked position, the open member engages with the lift lever by the operation of the open lever in one direction, thereby allowing the operation of the lift lever. When the open member is in the locked position, the open member idly engages with the lift lever by the operation of the open lever and then becomes engaged with the lift lever in the other direction when the open member is switched to the unlocked position from the locked position, thereby prohibiting the operation of the lift lever.
According to the known device, an unlocked state is defined when the open member is in the unlocked position while a locked state is defined when the open member is in the locked position. In the unlocked state, the open member is operated with the lift lever by engaging therewith due to the operation of a door handle and the like whereby the latch mechanism disengages from the striker. In the locked state, the open member idly engages with the lift lever and thus the lift lever is not operated even if the door handle is operated. The latch mechanism cannot disengage from the striker accordingly.
When the door handle and the door locking/unlocking member such as a door lock knob are operated at substantially the same time in the locked state, the aforementioned device is known to cause a problem as follows. When the door handle is operated before the operation of the door lock knob, the open member is moved to a full-stroke position under the locked state relative to the lift lever and then moved toward the unlocked position. In this case, the open member engages with the lift lever in the other direction and thus both the lift lever and the open member cannot be moved to the unlocked position. Thus, when the door handle is returned to a normal position from a pulled position, the door lock knob remains in the locked position even though the door lock knob is once operated to be unlocked (which is called a panic state). It is required to operate the door lock knob again to switch to the unlocked state, which causes the bother of operation. This kind of bother may occur in a door lock system for automatically switching to the unlocked state from the locked state by detecting an approach of the user's hand to the door handle. In this case, the door handle can be operated before the automatic switching to the unlocked state depending on the control timing.
A device disclosed in Japanese Patent Laid-Open Publication No. 11-166337 is known to solve the above-mentioned problem. FIG. 11 shows a structure of the disclosed device. The disclosed device includes a lift lever 90 for operating the latch mechanism from the engaged state to the disengaged state by engaging with or disengaging from the striker provided at the vehicle body, an open lever 91 operated by the operation of the door handle provided at the vehicle door, and a lock lever 92 provided at the vehicle door and operated by the operation of the door lock knob and the like. The disclosed device further includes an open member 93 operated with the lock lever 92 and movable between the unlocked position and the locked position.
The open member 93 engages with the lift lever 90 in S direction, thereby allowing the operation of the lift lever 90 when the open member 93 is in the unlocked position. The open member 93 also idly engages with the lift lever 90 in the locked position. The open member 93 includes a main link 94 connected to the open lever 91 and the lock lever 92, and a sub link 95 mounted on the main link 94 via a shaft 97 so that the sub link 95 rotates relative to the main link 94 and engageable with the lift lever 90. The open member 93 further includes a spring 96 disposed between the main link 94 and the sub link 95. FIG. 11 shows the locked state in which the open member 93 is in the locked position.
The aforementioned disclosed device is operated as follows in the locked state when the door handle and the door lock knob are operated substantially at the same time. The open member 93 is moved in substantially S direction in FIG. 11 while idly engaging with the lift lever 90 by the operation of the door handle and the like. Then, the open member 93 is moved in T direction, i.e. unlocked position, by the operation of the door lock knob and the like. In this case, the sub link 95 engages with the lift lever 90 in T direction and at the same time, rotates relative to the main link 94. The main link 94 of the open member 93 is therefore moved to the unlocked position together with the lock lever 92. When the door handle is returned to the normal position, the sub link 95 rotates relative to the main link 94 by a biasing force of the spring 96. Then, the open member 93 as a whole is returned to the unlocked initial position (i.e. recovered from the panic state). It is thus not required to operate the door lock knob again.
According to the above mentioned device, however, the sub link 95 is provided so as to rotate relative to the main link 94, and then the spring 96 is disposed between the main link 94 and the sub link 95. The structure of the device is thus complicated, which may be disadvantageous for the assembly condition of the device.
Thus, a need exists for a door lock device which can reduce the bother of operation without a complicated structure.